The pine saw-fly, Neodiprion sertifer, is present in the Soviet Union, Scandinavia, and Middle Europe, as well as in Canada and the United States of America. The adult insects swarm and copulate in August to September (Scandinavia), and the females lay their eggs in the pine-needles. After wintering the eggs hatch in May. The larvae live in colonies, and eat the pine-needles. This specie shows massive population growth in cyclic intervals, which last 3 to 4 years. During such a period the larvae consume large parts of the needle-mass in a stand. All needles but the ones present on new year shots are consumed. For this reason the pines will seldom die, even if they should become next to needle-less. The attack, however, results in a considerable growth decrease, which lasts for many years.
Biological tests have shown that several species of saw-fly being closely related to the pine saw-fly, Neodiprion sertifer, communicates by means of pheromones, i.e. specie specific volatile communication substances. Researchers (D. M. Jewett, F. Matsumura, and H. C. Coppel, Science, 192, 51 (1976)) have shown that both acetate and propionate of 3,7-dimethylpentadecan-2-ol (Formula: cf. FIG. 1) are active as attractants in trap experiments for males of the pine saw-fly (N.s.).
Chemical synthesis of different mixtures of diastereoisomers of 3,7-dimethylpentadecan-2-ol have been reported by several research groups (G. Magnusson, Tetrahedron Letter, 31, 2713 (1977); D. M. Jewett, F. Matsumura, and H. C. Coppel, J Chem. Ecol., 4, 277 (1978); P. J. Kociensky and J. M. Ansell, J Org. Chem., 42, 1102 (1977); P. Place, M-L. Roumestant, and J. Gore, J Org. Chem., 43, 1001 (1978)).
Other researchers (K. Mori and S. Tamada, Tetrahedron Letter, 35, 1279 (1979); S. Bystrom, H-E. Hogberg, and T. Norin, Tetrahedron, 37, 2249 (1981)) have synthetized acetates and propionates of (2S,3S,7S)-3,7-dimethylpentadecan-2-ol having 2,3-erythroconfiguration. These compounds were optically active, but not completely pure.
Furthermore, racemates of both acetates and propionates of 3,7-dimethylpentadecan-2-ol have been synthetized in erythro, as well as in threo form. (G. Magnusson, Tetrahedron, 34, 1385 (1978)).